mkfs.cramfs - make compressed ROM file system
mkfs.cramfs [options] directory file
Files on cramfs file systems are zlib-compressed one page at a time to allow
random read access. The metadata is not compressed, but is expressed in a
terse representation that is more space-efficient than conventional file
The file system is intentionally read-only to simplify its design;
random write access for compressed files is difficult to implement. cramfs
ships with a utility (mkcramfs(8)) to pack files into new cramfs
File sizes are limited to less than 16 MB.
Maximum file system size is a little under 272 MB. (The last file
on the file system must begin before the 256 MB block, but can extend past
The directory is simply the root of the directory tree that we want to
generate a compressed filesystem out of.
The file will contain the cram file system, which later can
Enable verbose messaging.
Treat all warnings as errors, which are reflected as
command exit status.
Use defined block size, which has to be divisible by page
Use defined file system edition number in
-N big, little, host
Use defined endianness. Value defaults to
Insert a file to cramfs file system.
Set name of the cramfs file system.
Pad by 512 bytes for boot code.
This option is ignored. Originally the -s turned
on directory entry sorting.
Make explicit holes.
Display help text and exit.
Display version information and exit.
operation error, such as unable to allocate memory